1. A group of herbivorous dinosaurs characterized by a hip structure similar to that of modern birds, including species such as Triceratops and Stegosaurus.
Usage: plural of ornithischian; paleontology term; scientific classification

Examples

• Ornithischians were one of the two major groups of dinosaurs that roamed Earth during the Mesozoic Era.
• Unlike saurischians, ornithischians had a pelvic structure that resembled modern bird anatomy.
• Triceratops and Ankylosaurus were among the most successful ornithischians of the Late Cretaceous period.
• Many ornithischians were quadrupedal herbivores that traveled in herds.
• Scientists study ornithischians to understand the diversity of dinosaur body plans and behaviors.